Amyloidosis (am-uh-loy-doh-sis) is a protein disorder. In this disease, proteins change shape (misfold), then bind together and form amyloid fibrils which deposit in organs. As amyloid fibrils build up, the tissues and organs may not work as well as they should. Our bodies make several proteins that can cause amyloidosis.
https://my.clevelandclinic.org/health/diseases/15718-amyloidosis-al-amyloid-light-chain